Often, in medical applications and other applications where maintaining sterile conditions is important or necessary, it is desirable to pump fluid through tubing without contact between the fluid and the pumping apparatus. Various types of tubing occluder pumps are known for this purpose, namely, peristaltic pumps and linear pumps. Linear pumps are also commonly known as finger pumps. In each of these types of pumps, fluid is pumped as a result of periodically occluding transverse sections of flexible tubing.
In a peristaltic pump, two or more rollers periodically longitudinally traverse a length of tubing while transversely occluding the cross section of tubing where contact is made to displace the fluid through the tube. The periodic traversal and occlusion of the length of tubing is achieved in a peristaltic pump by rotation of a pump head which carries two or more rollers. Usually, four rollers are utilized. The rollers traverse a section of tubing located between a housing and the pump head. Flat, cylindrical rollers have been used in the past to occlude the tubing against the housing which has a curvature generally corresponding to the radius of the pump head. The result is that the tubing is occluded between a roller and the housing in a manner similar to the occlusion of tubing between two flat surfaces.
In a linear pump, a plurality of occluding members periodically serially occlude different transverse sections of tubing located between the members and a housing or back-up plate. The occluding members linearly advance on and retract from the tubing in a direction normal to the housing or back-up plate.
It would be advantageous to provide a tubing occluder pump which requires less torque or power to pump a given volume of fluid. It would also be advantageous to provide a tubing occluder pump which extends the life of the tubing associated with the pump.